title: Exercise increases the plasma antioxidant capacity of adolescent athletes.
abstract: BACKGROUND
  The reactive oxygen species produced as a result of exercise might exceed an individual's antioxidant defence system. Various endogenous antioxidants are elevated in adult athletes, resulting in an improved antioxidant capacity. However, little is known about antioxidant defence in adolescents. The purpose of this study was to examine presumed adaptations of antioxidant capacity in exercising adolescents.
  
  
  METHODS
  Trolox-equivalent antioxidant capacity (TEAC), uric acid and nutritional antioxidants were measured in the plasma of 91 male and 98 female athletes (mean age 15.9 +/- 2.0 years) and compared to those of 18 male and 22 female sedentary controls (mean age 16.3 +/- 2.1 years). Antioxidant intake was calculated using 4-day dietary records.
  
  
  RESULTS
  Neither male nor female athletes showed differences in alpha-tocopherol, beta-carotene or ascorbate intake compared to controls. Plasma levels of alpha-tocopherol and carotenoids in athletes and controls did not differ either. Nevertheless, athletes of both sexes had higher TEAC values than their respective controls (male athletes 1.48 +/- 0.22 mmol/l vs. male controls 1.23 +/- 0.19 mmol/l, female athletes 1.47 +/- 0.20 mmol/l vs. female controls 1.15 +/- 0.04 mmol/l, p < 0.05).
  
  
  CONCLUSIONS
  Regular exercise enhances antioxidant capacity in adolescent athletes, independently of their dietary antioxidant intake, which indicates activity-related adaptations.
authors.affiliation: Department of Physiology and Pathophysiology, Institute of Nutritional Science, University of Potsdam, Potsdam, Germany. carlsohn@uni-potsdam.de
authors.forename: Anja
authors.initials: A
authors.lastname: Carlsohn
authors.forename: Sascha
authors.initials: S
authors.lastname: Rohn
authors.forename: Frank
authors.initials: F
authors.lastname: Bittmann
authors.forename: Jens
authors.initials: J
authors.lastname: Raila
authors.forename: Frank
authors.initials: F
authors.lastname: Mayer
authors.forename: Florian J
authors.initials: FJ
authors.lastname: Schweigert
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D000975:Antioxidants / Q000008:administration & dosage* / Q000378:metabolism*; D016022:Case-Control Studies; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D018384:Oxidative Stress / Q000502:physiology; D013177:Sports; D024502:alpha-Tocopherol / Q000097:blood; D019207:beta Carotene / Q000097:blood
chemical_list: D000975:Antioxidants; D019207:beta Carotene; D024502:alpha-Tocopherol